04. Wastewater irrigation: Hubli-Dharwad, India

04. Wastewater irrigation: Hubli-Dharwad, India

Title 04. Wastewater irrigation: Hubli-Dharwad, India
Publication TypeConference Paper
Year of PublicationSubmitted

A paper presented by Andrew Bradford, Robert Brook and Chandra Hunshal on 21-23 January 2003, Muldersdrift, South Africa.

Within the twin city of Hubli-Dharwad approximately 60 million l of wastewater is generated every day: this flows, untreated, from sewers and wastewater nallas (open drains) into the natural watercourses that flow into the city’s hinterland. In the semi-arid climate, where the summer temperatures exceed 35 degrees centigrade and the monsoon rains are erratic and unreliable, the wastewater is an extremely valuable resource for urban and peri-urban farmers and many extract it from the nallas and underground sewer pipes to irrigate their crops. This is considerably cheaper than constructing a borehole, which makes the practice more accessible and attractive to farmers with fewer financial resources. The wastewater also provides an irrigation source during the dry season, which enables farmers to sell their produce for three to five times the kharif (monsoon) season prices, while its high nutrient load increases crop yields and also reduces the need for costly fertilizer inputs. While this farming practice alleviates poverty for many urban and peri-urban farmers, it simultaneously places them, the consumers of their products and the environment at risk. The farmers have repeated close contact with the untreated wastewater, which is a major source of pathogens, and the high levels of anaemia found amongst them can be attributed to water-borne parasitic diseases and worm infestation. The wastewater also contains potentially injurious bio-medical waste (including disposable needles and syringes), which after tilling operations becomes half buried in the soils creating hazardous conditions for farmers that work in the fields. Unregulated and continuous irrigation with wastewater also leads to environmental problems such as salinisation, phytotoxicity (plant poisoning) and soil structure deterioration (soil clogging), which in India is commonly referred to as ‘sewage sickness’. [authors abstract]